Sulfur colors of the dioxazine series and method of preparing the same



Patented Aug. 14, 1951 OF THE DIOXAZINE SERIES AND METHQD OF PREPARING SULFUR COLORS THE SAME Gordon Bradbury Robbins, Claymont, Del.,- assignor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application June 22, 1949, Serial No. 100,746

7 Claims.

This invention relates to novel sulfur colors and to a method of preparing the same. For the purpose of this invention, a"sulfur color may be defined as one soluble in aqueous sodium sulfide, and capable of being applied to fabric b the standard sulfur dye procedure, that is by vatting in an aqueous sodium-sulfide bath, followed by oxidation on the fiber to the insoluble form.

It is known that sulfur dyes are relatively scarce in those portions of the spectrum ranging from orange, through red, to violet, On the other hand, sulfur dyes generally possess the advantages of being easily reducible, hence easily applicable to textile material, and of yielding furthermore, dyeings of good fastness qualities.

Accordingly, itis an'object of this invention to produce new sulfur colors of good tinctorial qualities and of desirable shades,"especially in the ranges of blue fund and red to orange. Another object is to provide amethod for producing sulfur colors of the dioxazine series in general which leads tODI'OdHCtS Of high quality and which is of general applicability, thereby onering a wide chcice'ofshades in the resulting product. Further important objects of this invention will become apparent as the description proceeds.

Sulfur dyes in general possess properties which make them ver 'desira'blefor commercial purposes. Outstanding amongthese properties, aside from their low cost, is their relative ease and economy of application. Thus, whereas anthraquinone vat dyes demand relatively expensive reducing agents (sodium hydrosulfite) and careful control of dyeing conditions in order to obtain level dyeings, sulfur dyes are reduced easily by cheap reagents (sodium sulfide) to give level dyeings with a minimum amount of attention to conditions of application. The dyeings from $11]- fur dyes, though not sofast to light and bleach as the anthraquinone vat dyes, are nearly as fast to washing. The light fastness of sulfur dyes is very good, however, compared to. azo dyes, and their wash vfastness is much superior to that group. Thus, sulfur dyes answer a definite need for inexpensive dyes of moderately good light fastness combined with very good wash fastness. Finally, sulfur colors are generallymarketed in powder form which dissolves-readily in the sodiumsulfide vat; hence sulfur colors are convenient to transport and to store.

It is clear from the aforegoing considerations thatthe lack of sulfur colorsin certainranges of the spectrum constitutes a-practical want of great'commercial significance. It is not merely that the absence of a :sulfurred, for instance,

minum chloride and sulfur monochloride.

deprives the textile manufacturer of theprivilege of producing red dyed textiles by-the aid of sulfur dyes. But even of greater commercial significance is the fact that the textile dyer-is handicapped whenhe desires-to shade available sulfur colors in the direction of red.

Thus, textile dyers, asarule, do not find it convenient to limit their production to colors or shades available-by the marketed dyestufis of a given class (say sulfur colors). More often, the artists design calls for the use of a color which is a shade different, one Way or another, from a given standard'product. To meet the requirement, the given color has to be shaded with another color.

Furthermore, when it is desired to shade-say a blue intoa reddish-blue, theobvious expedient of adding-a red color to the blue is not-in practice the best, inasmuch as the'brightness of the color may suffer from mixing such diverse shades. A more practical expedient is to shade the blue with a violet; in other words, it is preferable to have the shading color. as near as possible to the principal color, so as to avoid undue dullness in the resulting mixture.

The production of sulfur colors which would fill out the missing ranges in the spectrum thus becomes an economic. problem not only on its own merit, but also because it would enhance the utility of those ranges of the spectrum which are now available in'this field. In spite of its importance, however, this problem has not to my knowledge been solved'to date. Red shades in sulfur'colorshave cometo be looked upon by experts as an almost unattainable ideal, whilethe neighboring ranges of orange and violet have been but poorly satisfied'in the art to date.

To the extent that allusion to such colors may be found in the literature, they either require expensive initial materials or 'comp'lexprocesses of production, or the'resulting color is dull or of very low tinctorial power, making the 'colorhighly neconomical for practical: use.

In my copending application Serial No. 53,385

of October -'7,'1948, now Patent No. 2,50,153, I havedescribed a method for producing sulfurcolors of the dioxazine series by reacting upon dioxazine colors with a special sulfurizing agent comprising the complex addition product of alu- This method is excellent for itssimplicity and economy, but of course offers no opportunity for controlling the positions' of the entering sulfide-vattable groups.

My present invention offers an, improvement over said prior process in that I am able to control the location of the sulfide-vattable groups, as well as of any other auxochromic atoms or radicals in the molecule with respect to the fundamental triphendioxazine complex, thereby producing products of highest purity and tinctorial qualities. Also, my present method is of wider applicability and offers a wide choice in the desired structure of the resulting products, and consequently a wide range of shades in the resulting colors. My present method also leads to novel compounds which are structurally different from the compounds described and claimed in my copending application.

The improved process of my present invention synthesizes sulfide-vattable dioxazine colors by joining a triphendioxazine molecule to a nonchromophoric molecule bearing sulfide-vattable groups, by the aid of an amido linkage of the type CONR, wherein R stands for hydrogen, methyl or ethyl. Accordingly, the process of this invention starts on the one hand with a triphendioxazine color having two carboxy groups, and on the other hand with an aromatic or heterocyclic primary or secondary amine which is free of water-solubilizing groups, but bears atleast one sulfide-vattable group such as the thiocyano radical (SCN) or a polysulflde radical. densation of the two is effected by first converting the dicarboxy compound into the corresponding di-(carbonyl halide) compound by the aid of an acid halogenating agent such as thionyl chloride, phosphorus pentachloride or phosphorus trichloride, which dicarbonyl halide may be isolated or reacted directly, in situ, with the selected amine.

To illustrate this point, I may start with any dicarboxy-triphendioxazine, for instance 3,10- dicarboxy-6,l3-dichloro-triphendioxazine.

coon

(Example 2 of Ft, Pat. 789,805)

or with 2,9-dicarboxy-6,l3-dichloro-triphendioxazine, or with any other convenient triphendioxazine which has two COOH groups, or salts or esters thereof, in the 2,9 or 3,10-positions of the outer phenyl radicals of the triphendioxazine may bemNOsoN 4-thiocyano-aniline H; ONHOS ON N-methyl-4-thioeyano-ani1ine Con-' 2-amino-6-thiocya no-benzothiazole NH: HzN G Q 2,2-diamino-diphenyl-disulfide S ON HzN SON 2,4-dithiocyano-l-napthylamine etc.

Accordingly, the novel compounds of this invention may be defined by the general formula sents a radical of the benzene series bearing a thiocyano group.

My novel compounds are characterized by being soluble in aqueous sodium sulfide, being substantive to cotton from such solution, and being convertible into fast dyeings on the fiber after' exposure to air or oxidation in the manner customary with sulfur dyes.

Without limiting my invention, the following examples are given to illustrate my preferred mode of operation. vParts mentioned are by weight.

PART A.PREPARATION OF THE DYES Example I.-Without isolation of intermediate compound 1 part of 2,9-dicarboxy-6,l3-dichloro-triphen-.

dioxazine, 0.1 part of pyridine, 26 parts of orthodichlorobenzene and 3 parts of thionyl chloride are heated at reflux for 2 hours. Red-brown crystals of the acid-chloride appear during this step. The distillate is then allowed to escape until the temperature of the boiling reaction mixture increases to about 175 C. The reaction mixture is cooled to C. 2.5 parts of pyridine are added, followed by 1 to 1.5 part of 4-thiocyano-aniline. to 130 C. for one hour.

is filtered off, washed successively with alcohol and water, and dried.

Example II.With isolation of intermediate COCl compound 1 part of 3,l0-dicarboxy-6,13-dichloro-trlphen-.

dioxazine, 0.1 part of pyridine, 15 parts of ortho- The mixture is heated at It is then cooled, diluted 7 with 15 parts of alcohol and the red-brown solid answer.

57- dichlorobenzene, and :3 parts :of i? thionyl .-chloride.;. are heated to. reflux fr:2;'h0.urS;;. The distillate: is allowed to escape until the temperature in the. reaction mixture reaches-1709C. The: mixture is cooled and" diluted withrlO parts ofi: petroleum q ether; The product, which consists :ofxreddishorangecrystals, is filtered-off and washedwith; petroleum ether: It is then dried,; while taking-t. precaution to avoid unnecessary exposure to moist- 1 ture of the atmosphere.

The acid chloride thus prepared is added to 1.5 parts of 2-methoxy 4#thiocyano- 5 =chloroaniline in partsof pyridine: The mixture-.is.heated to 100-110 C. for one hour. It is cooled to C. and diluted with parts of water. The prod- 15 uct is filtered off, washed in turn with alcohol and water, and dried at 60-70 C. A bright, reddishora-nge powder isobtained.

Examplelfl.

One part of 3,10-dicarboxy-6,l3-dichlorotri phendioxazine is suspended in 10 parts of orthodichloro benzene. 1.2 parts of. phosphorus pentachloride is added and-the mixture is heated to reflux for half an hour. Sparts of solvent naphg5:

water, filtered and. washed. with waterand then; 5

with warm alcohol. The dark. orange product dyes cotton a bright orange shade.

Example I V- One part of 2,9-dicarboxy-G.l3 dichloro tri-- 0 phendioxazine is reacted with 3.5 parts ofrthionyl. chloride in 10 parts of 'ortho dichloro'benzeneand 0.1 part of pyridine at reflux for 2hours and then excess thionyl chloride is distilled off" until the temperature in thereaction mixture has risen from 130-140 C. to'1'l01'75 C. The mixture isfcooled and diluted with 5 parts of petroleum ether. The product which forms as red-brown crystals-during the reaction is filtered off and washed with 1119+ troleum ether. to moisture is kept at a minimum during. the? isolation.

One part of the acid chloride prepared above; is reacted with one part0)? 4,4"-diamino'-diphenyl' disulfide in 20' parts of pyridine-at 1009:110 C.: for one hour. The mixture iscooled tot40C'. and? diluted with partsof water. The dye is filtered? off and is washed first with water and-then-with': warm alcohol. The product is a brownish red powder.

Example. V

One part of the acid chloride from:';.2;9.-dicarboxy-6,l3-dichloro-triph'endioxazine'(preparedzas. in'the preceding example) is added;to*1.1'Parts-i of 2-amino-6-thiocyano-benzthiazole: (prepared' The dye is washed first withwater andithen: 70.

alcohol. The product is areddishebrowntpowder."

Example VI One part of the acid chloride.-.from. 2,9edicare boxy-6,13edichlor0-triphendi0xazineprepared as;

It is dried at c: Exposure 50 irrExampleeIV). and' one; part: of:.6,6 '.-di.(2.-amino.- I benzthiazyl) disulfide, (preparedz'byscaustic hysdrolysis of 2-amino-6-thiocyano-benzthiazole) are reacted in 25 parts of pyridine. The mixture iSheated to; C.Z for hour; It is then diluted" with 50 i parts of f water.

alcohol. 7

Example VII One partaof-utheacidl chloride from 6.13-di-.

ch-loro -triphendoxazine-2,9 dicarboxylic acid (prepared as in Example IV) is stirred with.0.75. part of- 4,4i-diaminoediphenyl-disulfide in, 18.. The

parts of pyridine at 25-30 C. for 18 hours. reaction mass .'is ..diluted with. 18 parts of water and .is .filtered. The product-is washed with waterv and: then withzhotalcoholand dried toa..-red.

brown powder.

Example VIII Onepart :of i the same; acid chloride as above is.- stirred With1'01 75 part of. 4,4-'-diamino-d-iphenyldisulfide in 40--parts of nitrobenzene and 3- parts a of-dimethyl aniline at 200-210 C. for 1 hour.

The 5. reaction; mass iscdiluted with. 60 parts of"- alcohol, filtered, washed with alcohol andwthen; with water.. Theproduct is..dried..to. ared brown.

powder.

Example IX One partof the acid chloride of Example IV andOllfi-partof the diamine specified in. Example.

IV are reacted in a mixture of 25 parts of benzene and 1 part of triethylamine at 80 C. for 1 hour.

The product'is' filtered; washedwith alcohol and" It is dried to a reddish-brown then with water. powder.

Example X- One part" of 6;l3 dichloro triphendioxazine 3,10-dicarbonyl chloride (prepared asiin Example II) and 018" part" of 2=methoxy-4=-thiocyano-5- chloro aniline are heated with 10 parts of pyridine for /2 hour at'85"-95"C. Themixture isdiluted with -10 parts -of water and filtered. The product is :washedfwith' water, then with hot alcohol anddried-.- A bright orange powder is obtained.

Example XI One part of triphendioxazine-3,'10 dicarbonyl chloride is treated'with"2,5 dichloro-i thiocyanoaniline (prepared-bythiocyanationof 2,5-.dichloro.

aniline) in 10 parts of pyridine underv the same conditions as used in Example X. The product 55? is isolated" in the same way to give a yellowpart "of thezdyeprepared under Example I, 2 parts ofisodium carbonate,- 10 parts of. sodium sulfide and 30=parts ofsalt in-2500 parts-of water. The

red-brown-idyestuff dissolves, in the bath giving-a.

When 100 parts-of cotton skein. are'treated in the :vat for one hour, a bright yellow color shows on the skein until it has been.-

pale yellow vat.

squeezed, rinsed, andoxidized in a bath. contain-v ing. 2. parts of sodium dichromate and 4 .parts of The.

skein develops a heavy dyeing of an: attractive red acetic" acid in. 2000..parts of warm water.

shade.

In a similar manner, the orange dyestuff prepared under.- Examplell. gives. a. pa v v twh The 1 product-21s filtered, washed with water and thenxw-ith hot 7 leaves the skin nearly white, changing 'to'a bright orange on aftertreatment.

Example B-2 acid acceptor and other features can be varied widely, as will be apparent to One skilled in the art.

I claim as my invention:

The Procedure f Example isrepeated 5 1. The process of producing sulfur dyestuffs of t that the 00101 therein used is replaced by the dioxazine series, which comprises reacting, in. a mixture of P of the dye prepared in the presence of a tertiary nitrogenous base, a p e I d P ts Of a brown Sulfur y P triphendioxazine compound of the general forpared by the thionation of 2,7-dimethyl-3,6-dimu1a amino-acridine according to U. S. Patent X 1,165.531. A brown vat is obtained, dyeing the skein a dark brown, which becomes a very reddish brown on aftertreatment. The dyeing is much 01 C] redder than that obtainable by using the unshaded brown dyestufi above. 0 N

In a similar manner other triphendioxazine X compounds having carboxy groups and other 1 V amines having sulfide-sensitive radicals may be wherein X is a member of the g up c t reacted with each other to form amides. The of hydrogen, halogenand methyl, with a nonquantity of amine employed relative to the quan- 2 chromophoric W ns lu am n d ed y tity of triphendioxazine compound may vary conth fo mula siderably, but care should be taken to have a Z SCN molar excess of the amine. The following table i Q shows various combinations synthesized by us and the shades obtainable from the resulting com- 25 Y Y1 pounds when dyed upon cotton by the sulfur-dye 2 procedure. wherein Z is a member of the group consisting of gg'f Acid Component Amine Component Shade on Cotton 1 4-Thiocyano-aniline r. R d

2,9-l21icarb oxy-6,13-dichloro-triphendioxazine o hlor 2,9-Dicarboxy-6,13-dibromo-triphendioxazine 2-1Methoxy-4-thiocyano-5-chloro-ani- U16. 2,5-Dich1oro-4-thiocyano-aniline e siinilar to Prod. No.

Z-Methoxy-4-thiocyano-aniline..

Yglrlower than Prod.

o. l. ,5-Dimethoxyi-thiocyano-aniline Bllurer 1 than Prod" o. 2-Amino-6-thiocyano-benzthiazole Do. 2-Amino-4,5-benzo-6-thiocyano-benz- Much bluer than thiazole. Prod. N o. 1.

-Thiocyano-aniline 2-Methoxy-4-thiocyano-5-chloro-a iline 2,5-Dichloro-4-thiocyano-aniline Like Prod. No. 1.

2-Methyl--thioyano-5-chloro-aniline 4,4'-Diamino-diphenyl disulflde 4-Thiocyano-aniline 0. 10. Like Prod. N o. 13. Ifiike Prod. No. 10.

do Do. 3,IO-Dicarboxy-fi,13-dibromo-tri' hendioxazinedo Orange. 2,9-Dicarboxy-6,l3-dichloro-trip endioxazine 4,4-Diami110-2,5,2,5-tetrach1oro-di- Yellower than Prod.

phenyl disulfide. N o. 1. do 4,4-Diamino-2,2-dichloro-5,5-di- Similar to Prod. No.

methyl diphenyl disulfide. 1.

21 -do 2,4-Dithiocyano-l-naphthylamine Bllnrer 1 than Prod.

o. 22 do 2-Amino4-methoxy 6-thiocyano-benz- Do.

thiazole.

23 do 6,6'-Di(2-amino-benzthiazyl) disulfide. Bll lrer1 than Prod.

O. 24 do 4,4-Diamino-2,2-dichloro-5,5-dimeth- Similar to Prod. No.

oxy-diphenyl disulfide. l.

25 do 4,4'-Diamino-5,5-dimethyl-diphenyl Yellower than Prod.

disulfide. N o. 1. 26 do 2-Amino-4-methyl-6-thiocya11o-benz- Blner than Prod.

. thiazole. N o. 1.

It will be understood that the above examples hydrogen, ethyl and methyl, and each of the are merely illustrative and that the details may be varied widely by those skilled in the art. For instance, the quantity of inert solvent may be varied considerably, being limited only on one side by the requirement to make the reaction-mass stirrable and on the other side by excessive losses of product due to solubility. The solvent used can be varied among a large number of different liquids which possess no reactive groups and possess a satisfactory boiling point, such as toluene, xylene, nitrobenzene and trichlorobenzene. The relative desirability of these solvents varies with their boiling points and solvent action on the final products.

6,13-dichloro-triphendioxazine 3,10-diicarbonyl Temperature, halogenating agent, use of an chloride) in the presence of pyridine with two 9 10 molecules of a. thiocyano-aniline to produce the '7. The bis 2,5'-dichl0r0 4'-thiocyanoani1ide corresponding bis-amide. of 3,10-dicarboxy-6,13-dichloro-triphendioxazine. 4. Sulfur dyestuffs of the dlOXaZll'le series char- GORDON BRADBURY ROBBINS acterized by the general formula NOS 10 K scN wherein X is a member of the group consisting REFERENCES CITED of hydrogen, halogen and th l 2 i member The following references are of record in the of the group consisting of hydrogen, ethyl and 15 file of this Patent: methyl, and each of the Ys represents a member UNITED STATES PATENTS of the group consisting of hydrogen, chlorine, Number Name Date methyl and methoxy. 2 355 497 Z 8 1944 5. The bis -4-thiocyan0ani1ide of 2,9 -dicar- W1 gmeyer boxy-6,13-dich1orotriphendioxazine. 20 FOREIGN A ENTS 6. The bis 2-meth0xy 5-ch1or0 4'-thiocy- Number Country t anoanilide of 3,10-dicarboxy 6,13 dichloro-tri- 223,481 Great Britain Oct. 23, 1924 phendioxazine. 454,302 Great Britain Sept. 25, 1936 

4. SULFUR DYESTUFFS OF THE DIOXAZINE SERIES CHARACTERIZED BY THE GENERAL FORMULA 